lkml.org 
[lkml]   [2010]   [Nov]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
From
On Mon, Nov 15, 2010 at 7:45 PM, Jeff Law <law@redhat.com> wrote:
> On 11/08/10 03:49, Richard Guenther wrote:
>>
>> On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen<andi@firstfloor.org>  wrote:
>>>
>>> Andreas Schwab<schwab@linux-m68k.org>  writes:
>>>>
>>>> The asm fails to mention that it modifies *regs.
>>>
>>> It has a memory clobber, that should be enough, no?
>>
>> No.  A memory clobber does not cover automatic storage.
>
> A memory clobber should clobber anything in memory, including autos in
> memory; if it doesn't, then that seems like a major problem.  I'd like to
> see the rationale behind not clobbering autos in memory.

Non-address taken automatic storage. (note that we don't excercise this
in optimization yet)

It's difficult to model thins kind of non-aliased memory with this kind
of aliasing mechanism (apart from taking all asms as clobbering
everything as we currently do).

Richard.

> Jeff
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2010-11-15 23:09    [W:0.428 / U:0.748 seconds]
©2003-2014 Jasper Spaans. Advertise on this site